study of the interactions between organisms and between organisms and their environment

includes all organisms living in an area and the physical environment with which these organisms interact.

interdisciplinary studies in natural sciences including geology, climatology, hydrology, ecology, and their interaction with social sciences such as economics, political science, sociology, anthropology, geography

• social movement for protecting earth’s life support systems and living organisms

What keeps us alive?

-Amount of biologically productive land and water required to supply a population with resources. -It measures the environmental impact of populations in different countries on the environment.

Resource that exists in a fixed amount in the earth's crust. Requires millions to billions of years to regenerate by geological, physical, and chemical processes.

– Highest rate at which a renewable resource can be used without reducing its available supply.

Depletion or destruction of a potentially renewable resource such as soil, grassland, forest, or wildlife that is used faster than it is naturally replenished

What are Our Greatest Environmental Problems?

All species descended from earlier ancestral species. -Changing genetic make- up in a population over time. -Accepted scientific explanation of how animals adapt and survive

long term, large scale changes in the population

small genetic changes in the population

all genes in a population

random change in structure of DNA. Generally , a mutation is beneficial for survival

individuals that have traits that benefit survival.

some individuals leave more offspring than do others due to traits that favor survivalsome individuals leave more offspring than do others due to traits that favor survival

(heritable) trait helps survival and reproduction under current environmental conditions

role of organism in the ecosystem. Includes interaction with biotic and abiotic factors.

physical location

extinction normal and slow rates (e.g., one species of bird will go extinct every estimated 400 years)

extinction that is quick, involving many species at once

higher than mass extinction (Ice Age/Ordovician) – 99% of species that have existed on earth are now extinct

after mass extinctions, numerous new species evolve to fill vacated niches.

accelerated extinctionaccelerated extinction

artificially selecting superior genetic traits • Agriculture • Hatcheries • pets

• Gene splicing • Species creation in laboratories • Takes less time than artificial selection

• Many failures (1% success rate) • Lead to more abortions? Only for the wealthy?

majority of marine species (90%) • most commercial fisheries and interaction with land and humans

90% of ocean area

where rivers meet ocean